Dizziness/vertigo is the third most common presenting complaint to primary care clinics. In 2015, it accounted for 10 million Canadian emergency department visits and over a thousand unique emergency department visits at Health Sciences North (1, 2). The majority of cases are resulting from one of several benign self-limiting processes (3). The most common cause is benign paroxysmal positional vertigo (BPPV)(3). Currently the vast majority of patients who are diagnosed with BPPV do not have any bedside diagnostic tests performed in the emergency department(4). We performed a historical cohort study over a 3-year period identifying 2,500 patients with a primary complaint of dizziness. Our preliminary data shows that even those who undergo bedside diagnostic tests 4 in every 5 are actually performed on patients who do not have clinical symptoms suggestive of BPPV and thus are inappropriate. Neuroimaging is not indicated in patients with BPPV, however 1 in 3 of those diagnosed will also undergo computed tomography of the head. The current investigation, diagnosis and treatment of BPPV are extremely poor, exposing patients to prolonged symptoms, unnecessary radiation and prolonged emergency department visits.
Inclusion; >18 years patients presenting with a primary complaint of intermittent dizziness, unsteadiness, ataxia, imbalance or vertigo.
Exclusion; Dizziness >14 days, focal sensory or motor deficits on history of physical exam. Unable to walk >3 steps unaided (from a baseline of ambulating independently). Glasgow coma scale<15. Cervical spine pathology that limits neck manipulation. Systolic blood pressure <90.
We anticipate an average of 25 patients per month at our smallest site. For our primary process outcome compliance with the BPPV algorithm, we will have retrospective data available over 43 months (or a total of 1075 patients) and post-intervention data over 9 months (225 patients), all from routinely collected sources. Minimum recommendations for robust interrupted time series analyses are 8-12 pre and 8-12 post-intervention measurements. Based on these assumptions (pre-intervention intercept of 0.07, no pre-intervention slope, and no serial autocorrelation), we have 80% power to detect an absolute increase from pre- to post-intervention of 5.54% (or a proportion of 0.07 pre to 0.1254 post) using a two-sized test at the 5% level of significance. Our anticipated increase far exceeds this estimate, so even after accounting for a possible secular trend and serial autocorrelation, we are well-powered to detect an effect of the intervention. These calculations will be refined once pre-intervention data are available.
Our aim is to develop and implement an educational intervention to facilitate implementation of the 2017 BPPV pathway in addition to monitoring and sustaining its use. We hope that this will reduce radiation exposure, improve symptom resolution and ultimately improve patient care.
- Newman-Toker DE, Hsieh Y-H, Camargo Jr CA, Pelletier AJ, Butchy GT, Edlow JA. Spectrum of dizziness visits to US emergency departments: cross-sectional analysis from a nationally representative sample. Mayo Clinic Proceedings, 2008. Elsevier: 765-75.
- Kruschinski C, Hummers-Pradier E. Diagnosing dizziness in the emergency and primary care settings. Mayo Clinic Proceedings, 2008. Elsevier: 1297-8.
- Neuhauser H, Von Brevern M, Radtke A, Lezius F, Feldmann M, Ziese T, et al. Epidemiology of vestibular vertigo A neurotologic survey of the general population. Neurology. 2005;65(6):898-904.
- von Brevern M, Radtke A, Lezius F, Feldmann M, Ziese T, Lempert T, et al. Epidemiology of benign paroxysmal positional vertigo: a population based study. J Neurol Neurosurg Psychiatry. 2007;78(7):710-5.
- Bhattacharyya N, Baugh RF, Orvidas L, Barrs D, Bronston LJ, Cass S, et al. Clinical practice guideline: benign paroxysmal positional vertigo. Otolaryngology–Head and Neck Surgery. 2008;139(5_suppl):47-81.